Hall sensor elements based on the Hall effect are used in wide areas of technology for measuring the magnetic flux density of magnetic fields and also for contactless measurement of currents as well as contactless transducers, e.g., for wear-free detection of the position of shafts, actuators and the like. A Hall sensor element is generally composed of a semiconductor substrate wafer having four contact terminals for electrical connection to an external trigger circuit. Of the four contact terminals, two contact terminals are provided for applying an operating current through an active semiconductor area of the sensor element, while the two other contact terminals are used to detect the Hall voltage. The Hall voltage is perpendicular to the direction of the magnetic flux and of the current flux in the active semiconductor area.
German patent document DE 10 2006 017 910 A1 discusses a so-called horizontal Hall sensor element, in which the operating current and the Hall voltage run horizontally in the plane of the main surface of the semiconductor substrate. Horizontal Hall sensor elements are relatively easy to manufacture using traditional CMOS processes for manufacturing semiconductor structures, sensing flux density components of magnetic fields directed perpendicularly to the plane of the substrate. A multidimensional measurement of magnetic fields such as that required in compass applications, for example, is possible using horizontal Hall sensor elements by positioning multiple discrete semiconductor substrate wafers, on each of which a horizontal Hall sensor element is formed, perpendicular to various spatial directions, but this is associated with high manufacturing costs and space requirements.
German patent document DE 10 2006 017 910 A1 also discusses a vertical Hall sensor element in which the operating current and the Hall voltage run in a plane vertical to the substrate surface, so that flux density components of magnetic fields directed parallel to the plane of the substrate are sensed. The vertical Hall sensor element includes a plurality of contact areas at the main surface of a semiconductor area extending into the substrate. Nonconducting barrier areas extending into the semiconductor area, starting from the main surface, are situated between neighboring contact surfaces to keep an operating current, which is fed between two contact surfaces in the semiconductor area at a distance from the main surface. However, the problem arising here is that the conductivity for the charge carriers in deeper regions of the active semiconductor area is much lower than that at the surface of the semiconductor material, which may be silicon, so that such a vertical Hall sensor element is only marginally efficient.
A structure having multiple horizontal Hall sensor elements on a single semiconductor substrate wafer and an additional structured ferromagnetic layer, which deflects magnetic field components which are parallel to the surface of the semiconductor substrate wafer into local vertical fields, is proposed by C. Schott et al., but requires a high manufacturing effort because the structure cannot be manufactured using traditional processes for manufacturing semiconductor structures (C. Schott et al., CMOS Single-Chip Electronic Compass with Microcontroller, in: H. Casier et al. [eds.], Analog Circuit Design: Sensors, Actuators and Power Drivers; Integrated Power Amplifiers from Wireline to RF; Very High Frequency Front Ends, pages 55-69, Springer Science+Business Media B.V., 2008).